TWITTER

Michael Clarke, the former director of the defence think tank Rusi, said that relations between President Trump and US agencies had “got worse”.

He told BBC Radio 4: “After the election, it was hoped that the relationship between President Trump and the American agencies would settle down and it hasn’t.”

Mr Spicer said Mr Trump stood by his allegations.

GCHQ is one of three UK intelligence and security agencies, along with MI5 and MI6. It delivers signals intelligence – the intercepting of communication between people or electronic devices – to the prime minister and foreign secretary.

The agency credits its “particularly strong” relationship with its US equivalent, the National Security Agency, to the collaboration it began at Bletchley Park during World War Two.